In case you missed it, with CRM 2015 update 1 (and later), server side SharePoint integration is supported for CRM online customers with SharePoint on premises. One additional detail you should not miss is that the grid control is now deprecated. This does not mean that it won’t work, but that it will be taken away in the near future. This means that if you are upgrading you are encouraged to move to server-side integration if you currently use the grid control.